foil1

 
Pronunciation: /fɔɪl/

verb

[with object]
  • prevent (something considered wrong or undesirable) from succeeding: a brave policewoman foiled the armed robbery
  • frustrate the efforts or plans of: their rivals were foiled by the weather
  • Hunting (of a hunted animal) run over or cross (ground or a scent or track) in such a way as to confuse the hounds.

noun

  • 1 Hunting the track or scent of a hunted animal.
  • 2 archaic a setback in an enterprise; a defeat.

Origin:

Middle English (in the sense 'trample down'): perhaps from Old French fouler 'to full cloth, trample', based on Latin fullo 'fuller'. Compare with full2